Dane Michael’s review published on Letterboxd:
Feels weird to be somewhat in the middle on something that seems to inspire either intense love or intense hate.
I definitely appreciate what this is going for, especially after thinking about it and talking to people smarter than me, and am able to give it the Verhoeven reading that the intense ugliness and emptiness is part of the point. Some of the shots of Pump It Up also remind me of Harmony Korine's Spring Breakers, which I say as a high compliment. Demi Moore is really great, and I give her a lot of credit for doing something like this. I also appreciate that in an age of bloodless Elevated Horror that this goes for broke in terms of the gore and blood. The last 20 minutes really is something, folks!
With that said, I am not sure that the central premise makes total sense. Without going too deep into it, it is never made clear why the Demi Moore character would want to use The Substance, since it is never really said how exactly she benefits from the arrangement. I also think that, even though I can appreciate the Verhoeven-esque satire, this is a pretty un-dynamic, relentless movie that never takes a second to breathe, which makes it hard to fully connect to anything that is happening.
Still, all-in-all, a pretty wild time that is definitely worth experiencing!